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    <p>I admit I have little experience here, but have you seen the exception demo code example? It seems to contain exactly the kind of sequence you are hoping to find.</p> <p>Basically, you start by setting up the personality to behave as in C++:</p> <pre><code>llvm::Function *personality = module.getFunction("__gxx_personality_v0"); </code></pre> <p>You then create the landingpad with that personality and define its type:</p> <pre><code>llvm::LandingPadInst *caughtResult = builder.CreateLandingPad(ourCaughtResultType, personality, numExceptionsToCatch, "landingPad"); </code></pre> <p>Setting up the types to catch:</p> <pre><code>for (unsigned i = 0; i &lt; numExceptionsToCatch; ++i) { // Set up type infos to be caught caughtResult-&gt;addClause(module.getGlobalVariable( ourTypeInfoNames[exceptionTypesToCatch[i]])); } </code></pre> <p>And signalling it's a cleanup handler:</p> <pre><code>caughtResult-&gt;setCleanup(true); </code></pre> <p>This is it, I believe; now you can get the exception itself:</p> <pre><code>llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0); </code></pre> <p>The <a href="https://llvm.org/viewvc/llvm-project/llvm/trunk/examples/ExceptionDemo/ExceptionDemo.cpp?view=markup&amp;sortby=file" rel="noreferrer">ExceptionDemo.cpp</a> file, from which these code segments are taken, contains a fuller sequence; specifically, it shows how to check the type root of the caught exception and branch into a specific block - your cleanup code - when it matches something:</p> <pre><code>llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1); // FIXME: Redundant storage which, beyond utilizing value of // caughtResultStore for unwindException storage, may be alleviated // altogether with a block rearrangement builder.CreateStore(caughtResult, caughtResultStorage); builder.CreateStore(unwindException, exceptionStorage); builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag); // Retrieve exception_class member from thrown exception // (_Unwind_Exception instance). This member tells us whether or not // the exception is foreign. llvm::Value *unwindExceptionClass = builder.CreateLoad(builder.CreateStructGEP( builder.CreatePointerCast(unwindException, ourUnwindExceptionType-&gt;getPointerTo()), 0)); // Branch to the externalExceptionBlock if the exception is foreign or // to a catch router if not. Either way the finally block will be run. builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass, llvm::ConstantInt::get(builder.getInt64Ty(), ourBaseExceptionClass)), exceptionRouteBlock, externalExceptionBlock); </code></pre> <p>Finally, an additional example, along with explanations, is available <a href="http://blog.llvm.org/2011/11/llvm-30-exception-handling-redesign.html" rel="noreferrer">on the blog post that introduced the new exception handling mechanism</a>.</p>
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    1. COthat example ExceptionDemo is interesting, i didn't knew about it, thanks. Something that raises my attention is that the llvm::Function is created for `ourPersonality` and used in the landing pad, but i don't see anywhere a mapping from this function to the address of the actual `ourPersonality` function. Is `getFunction` doing symbol resolution by default if the mapping is empty?. I couldn't find any documentation for that 'feature'
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    2. CO@lurscher I don't know; I suspect it has something to do with the `_Unwind_Reason_Code` defined on its definition (which appears in the same file), but I'm just not familiar enough with that whole area, I'm afraid.
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